A.Compilation fails.
B.Nothing is added to the file system.
C.Only a new file is created on the file system.
D.Only a new directory is created on the file system.
E.Both a new file and a new directory are created on the file system.

A.Compilation fails.
B.An exception is thrown at runtime.
C.Synchronizing the run（） method would make the class thread-safe.
D.The data in variable "x" are protected from concurrent access problems.
E.Declaring the doThings（） method as static would make the class thread-safe.